/*****************************************************************************
* fsm.c - Network Control Protocol Finite State Machine program file.
*
* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
* portions Copyright (c) 1997 by Global Election Systems Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 03-01-01 Marc Boucher <marc@mbsi.ca>
*   Ported to lwIP.
* 97-12-01 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
*   Original based on BSD fsm.c.
*****************************************************************************/
/*
 * fsm.c - {Link, IP} Control Protocol Finite State Machine.
 *
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
 * TODO:
 * Randomize fsm id on link/init.
 * Deal with variable outgoing MTU.
 */

#include "lwip/opt.h"

#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */

#include "ppp_impl.h"
#include "pppdebug.h"

#include "fsm.h"

#include <string.h>

#if PPP_DEBUG
static const char* ppperr_strerr[] = {
	"LS_INITIAL",  /* LS_INITIAL  0 */
	"LS_STARTING", /* LS_STARTING 1 */
	"LS_CLOSED",   /* LS_CLOSED   2 */
	"LS_STOPPED",  /* LS_STOPPED  3 */
	"LS_CLOSING",  /* LS_CLOSING  4 */
	"LS_STOPPING", /* LS_STOPPING 5 */
	"LS_REQSENT",  /* LS_REQSENT  6 */
	"LS_ACKRCVD",  /* LS_ACKRCVD  7 */
	"LS_ACKSENT",  /* LS_ACKSENT  8 */
	"LS_OPENED"    /* LS_OPENED   9 */
};
#endif /* PPP_DEBUG */

static void fsm_timeout(void*);
static void fsm_rconfreq(fsm*, u_char, u_char*, int);
static void fsm_rconfack(fsm*, int, u_char*, int);
static void fsm_rconfnakrej(fsm*, int, int, u_char*, int);
static void fsm_rtermreq(fsm*, int, u_char*, int);
static void fsm_rtermack(fsm*);
static void fsm_rcoderej(fsm*, u_char*, int);
static void fsm_sconfreq(fsm*, int);

#define PROTO_NAME(f) ((f)->callbacks->proto_name)

int peer_mru[NUM_PPP];


/*
 * fsm_init - Initialize fsm.
 *
 * Initialize fsm state.
 */
void
fsm_init(fsm* f)
{
	f->state = LS_INITIAL;
	f->flags = 0;
	f->id = 0;        /* XXX Start with random id? */
	f->timeouttime = FSM_DEFTIMEOUT;
	f->maxconfreqtransmits = FSM_DEFMAXCONFREQS;
	f->maxtermtransmits = FSM_DEFMAXTERMREQS;
	f->maxnakloops = FSM_DEFMAXNAKLOOPS;
	f->term_reason_len = 0;
}


/*
 * fsm_lowerup - The lower layer is up.
 */
void
fsm_lowerup(fsm* f)
{
	int oldState = f->state;

	LWIP_UNUSED_ARG(oldState);

	switch(f->state) {
		case LS_INITIAL:
			f->state = LS_CLOSED;
			break;

		case LS_STARTING:
			if(f->flags & OPT_SILENT) {
				f->state = LS_STOPPED;
			} else {
				/* Send an initial configure-request */
				fsm_sconfreq(f, 0);
				f->state = LS_REQSENT;
			}

			break;

		default:
			FSMDEBUG(LOG_INFO, ("%s: Up event in state %d (%s)!\n",
			                    PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}

	FSMDEBUG(LOG_INFO, ("%s: lowerup state %d (%s) -> %d (%s)\n",
	                    PROTO_NAME(f), oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
}


/*
 * fsm_lowerdown - The lower layer is down.
 *
 * Cancel all timeouts and inform upper layers.
 */
void
fsm_lowerdown(fsm* f)
{
	int oldState = f->state;

	LWIP_UNUSED_ARG(oldState);

	switch(f->state) {
		case LS_CLOSED:
			f->state = LS_INITIAL;
			break;

		case LS_STOPPED:
			f->state = LS_STARTING;

			if(f->callbacks->starting) {
				(*f->callbacks->starting)(f);
			}

			break;

		case LS_CLOSING:
			f->state = LS_INITIAL;
			UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
			break;

		case LS_STOPPING:
		case LS_REQSENT:
		case LS_ACKRCVD:
		case LS_ACKSENT:
			f->state = LS_STARTING;
			UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
			break;

		case LS_OPENED:
			if(f->callbacks->down) {
				(*f->callbacks->down)(f);
			}

			f->state = LS_STARTING;
			break;

		default:
			FSMDEBUG(LOG_INFO, ("%s: Down event in state %d (%s)!\n",
			                    PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}

	FSMDEBUG(LOG_INFO, ("%s: lowerdown state %d (%s) -> %d (%s)\n",
	                    PROTO_NAME(f), oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
}


/*
 * fsm_open - Link is allowed to come up.
 */
void
fsm_open(fsm* f)
{
	int oldState = f->state;

	LWIP_UNUSED_ARG(oldState);

	switch(f->state) {
		case LS_INITIAL:
			f->state = LS_STARTING;

			if(f->callbacks->starting) {
				(*f->callbacks->starting)(f);
			}

			break;

		case LS_CLOSED:
			if(f->flags & OPT_SILENT) {
				f->state = LS_STOPPED;
			} else {
				/* Send an initial configure-request */
				fsm_sconfreq(f, 0);
				f->state = LS_REQSENT;
			}

			break;

		case LS_CLOSING:
			f->state = LS_STOPPING;

		/* fall through */
		case LS_STOPPED:
		case LS_OPENED:
			if(f->flags & OPT_RESTART) {
				fsm_lowerdown(f);
				fsm_lowerup(f);
			}

			break;
	}

	FSMDEBUG(LOG_INFO, ("%s: open state %d (%s) -> %d (%s)\n",
	                    PROTO_NAME(f), oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
}

#if 0 /* backport pppd 2.4.4b1; */
/*
 * terminate_layer - Start process of shutting down the FSM
 *
 * Cancel any timeout running, notify upper layers we're done, and
 * send a terminate-request message as configured.
 */
static void
terminate_layer(fsm* f, int nextstate)
{
	/* @todo */
}
#endif

/*
 * fsm_close - Start closing connection.
 *
 * Cancel timeouts and either initiate close or possibly go directly to
 * the LS_CLOSED state.
 */
void
fsm_close(fsm* f, char* reason)
{
	int oldState = f->state;

	LWIP_UNUSED_ARG(oldState);

	f->term_reason = reason;
	f->term_reason_len = (reason == NULL ? 0 : (int)strlen(reason));

	switch(f->state) {
		case LS_STARTING:
			f->state = LS_INITIAL;
			break;

		case LS_STOPPED:
			f->state = LS_CLOSED;
			break;

		case LS_STOPPING:
			f->state = LS_CLOSING;
			break;

		case LS_REQSENT:
		case LS_ACKRCVD:
		case LS_ACKSENT:
		case LS_OPENED:
			if(f->state != LS_OPENED) {
				UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
			} else if(f->callbacks->down) {
				(*f->callbacks->down)(f);  /* Inform upper layers we're down */
			}

			/* Init restart counter, send Terminate-Request */
			f->retransmits = f->maxtermtransmits;
			fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
			          (u_char*) f->term_reason, f->term_reason_len);
			TIMEOUT(fsm_timeout, f, f->timeouttime);
			--f->retransmits;

			f->state = LS_CLOSING;
			break;
	}

	FSMDEBUG(LOG_INFO, ("%s: close reason=%s state %d (%s) -> %d (%s)\n",
	                    PROTO_NAME(f), reason, oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
}


/*
 * fsm_timeout - Timeout expired.
 */
static void
fsm_timeout(void* arg)
{
	fsm* f = (fsm*) arg;

	switch(f->state) {
		case LS_CLOSING:
		case LS_STOPPING:
			if(f->retransmits <= 0) {
				FSMDEBUG(LOG_WARNING, ("%s: timeout sending Terminate-Request state=%d (%s)\n",
				                       PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
				/*
				 * We've waited for an ack long enough.  Peer probably heard us.
				 */
				f->state = (f->state == LS_CLOSING) ? LS_CLOSED : LS_STOPPED;

				if(f->callbacks->finished) {
					(*f->callbacks->finished)(f);
				}
			} else {
				FSMDEBUG(LOG_WARNING, ("%s: timeout resending Terminate-Requests state=%d (%s)\n",
				                       PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
				/* Send Terminate-Request */
				fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
				          (u_char*) f->term_reason, f->term_reason_len);
				TIMEOUT(fsm_timeout, f, f->timeouttime);
				--f->retransmits;
			}

			break;

		case LS_REQSENT:
		case LS_ACKRCVD:
		case LS_ACKSENT:
			if(f->retransmits <= 0) {
				FSMDEBUG(LOG_WARNING, ("%s: timeout sending Config-Requests state=%d (%s)\n",
				                       PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
				f->state = LS_STOPPED;

				if((f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished) {
					(*f->callbacks->finished)(f);
				}
			} else {
				FSMDEBUG(LOG_WARNING, ("%s: timeout resending Config-Request state=%d (%s)\n",
				                       PROTO_NAME(f), f->state, ppperr_strerr[f->state]));

				/* Retransmit the configure-request */
				if(f->callbacks->retransmit) {
					(*f->callbacks->retransmit)(f);
				}

				fsm_sconfreq(f, 1);    /* Re-send Configure-Request */

				if(f->state == LS_ACKRCVD) {
					f->state = LS_REQSENT;
				}
			}

			break;

		default:
			FSMDEBUG(LOG_INFO, ("%s: UNHANDLED timeout event in state %d (%s)!\n",
			                    PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}
}


/*
 * fsm_input - Input packet.
 */
void
fsm_input(fsm* f, u_char* inpacket, int l)
{
	u_char* inp = inpacket;
	u_char code, id;
	int len;

	/*
	* Parse header (code, id and length).
	* If packet too short, drop it.
	*/
	if(l < HEADERLEN) {
		FSMDEBUG(LOG_WARNING, ("fsm_input(%x): Rcvd short header.\n",
		                       f->protocol));
		return;
	}

	GETCHAR(code, inp);
	GETCHAR(id, inp);
	GETSHORT(len, inp);

	if(len < HEADERLEN) {
		FSMDEBUG(LOG_INFO, ("fsm_input(%x): Rcvd illegal length.\n",
		                    f->protocol));
		return;
	}

	if(len > l) {
		FSMDEBUG(LOG_INFO, ("fsm_input(%x): Rcvd short packet.\n",
		                    f->protocol));
		return;
	}

	len -= HEADERLEN;    /* subtract header length */

	if(f->state == LS_INITIAL || f->state == LS_STARTING) {
		FSMDEBUG(LOG_INFO, ("fsm_input(%x): Rcvd packet in state %d (%s).\n",
		                    f->protocol, f->state, ppperr_strerr[f->state]));
		return;
	}

	FSMDEBUG(LOG_INFO, ("fsm_input(%s):%d,%d,%d\n", PROTO_NAME(f), code, id, l));

	/*
	 * Action depends on code.
	 */
	switch(code) {
		case CONFREQ:
			fsm_rconfreq(f, id, inp, len);
			break;

		case CONFACK:
			fsm_rconfack(f, id, inp, len);
			break;

		case CONFNAK:
		case CONFREJ:
			fsm_rconfnakrej(f, code, id, inp, len);
			break;

		case TERMREQ:
			fsm_rtermreq(f, id, inp, len);
			break;

		case TERMACK:
			fsm_rtermack(f);
			break;

		case CODEREJ:
			fsm_rcoderej(f, inp, len);
			break;

		default:
			FSMDEBUG(LOG_INFO, ("fsm_input(%s): default: \n", PROTO_NAME(f)));

			if(!f->callbacks->extcode ||
			        !(*f->callbacks->extcode)(f, code, id, inp, len)) {
				fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
			}

			break;
	}
}


/*
 * fsm_rconfreq - Receive Configure-Request.
 */
static void
fsm_rconfreq(fsm* f, u_char id, u_char* inp, int len)
{
	int code, reject_if_disagree;

	FSMDEBUG(LOG_INFO, ("fsm_rconfreq(%s): Rcvd id %d state=%d (%s)\n",
	                    PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));

	switch(f->state) {
		case LS_CLOSED:
			/* Go away, we're closed */
			fsm_sdata(f, TERMACK, id, NULL, 0);
			return;

		case LS_CLOSING:
		case LS_STOPPING:
			return;

		case LS_OPENED:

			/* Go down and restart negotiation */
			if(f->callbacks->down) {
				(*f->callbacks->down)(f);  /* Inform upper layers */
			}

			fsm_sconfreq(f, 0);    /* Send initial Configure-Request */
			break;

		case LS_STOPPED:
			/* Negotiation started by our peer */
			fsm_sconfreq(f, 0);    /* Send initial Configure-Request */
			f->state = LS_REQSENT;
			break;
	}

	/*
	* Pass the requested configuration options
	* to protocol-specific code for checking.
	*/
	if(f->callbacks->reqci) {     /* Check CI */
		reject_if_disagree = (f->nakloops >= f->maxnakloops);
		code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
	} else if(len) {
		code = CONFREJ;      /* Reject all CI */
	} else {
		code = CONFACK;
	}

	/* send the Ack, Nak or Rej to the peer */
	fsm_sdata(f, (u_char)code, id, inp, len);

	if(code == CONFACK) {
		if(f->state == LS_ACKRCVD) {
			UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
			f->state = LS_OPENED;

			if(f->callbacks->up) {
				(*f->callbacks->up)(f);  /* Inform upper layers */
			}
		} else {
			f->state = LS_ACKSENT;
		}

		f->nakloops = 0;
	} else {
		/* we sent CONFACK or CONFREJ */
		if(f->state != LS_ACKRCVD) {
			f->state = LS_REQSENT;
		}

		if(code == CONFNAK) {
			++f->nakloops;
		}
	}
}


/*
 * fsm_rconfack - Receive Configure-Ack.
 */
static void
fsm_rconfack(fsm* f, int id, u_char* inp, int len)
{
	FSMDEBUG(LOG_INFO, ("fsm_rconfack(%s): Rcvd id %d state=%d (%s)\n",
	                    PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));

	if(id != f->reqid || f->seen_ack) {    /* Expected id? */
		return; /* Nope, toss... */
	}

	if(!(f->callbacks->ackci ? (*f->callbacks->ackci)(f, inp, len) : (len == 0))) {
		/* Ack is bad - ignore it */
		FSMDEBUG(LOG_INFO, ("%s: received bad Ack (length %d)\n",
		                    PROTO_NAME(f), len));
		return;
	}

	f->seen_ack = 1;

	switch(f->state) {
		case LS_CLOSED:
		case LS_STOPPED:
			fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
			break;

		case LS_REQSENT:
			f->state = LS_ACKRCVD;
			f->retransmits = f->maxconfreqtransmits;
			break;

		case LS_ACKRCVD:
			/* Huh? an extra valid Ack? oh well... */
			UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
			fsm_sconfreq(f, 0);
			f->state = LS_REQSENT;
			break;

		case LS_ACKSENT:
			UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
			f->state = LS_OPENED;
			f->retransmits = f->maxconfreqtransmits;

			if(f->callbacks->up) {
				(*f->callbacks->up)(f);  /* Inform upper layers */
			}

			break;

		case LS_OPENED:

			/* Go down and restart negotiation */
			if(f->callbacks->down) {
				(*f->callbacks->down)(f);  /* Inform upper layers */
			}

			fsm_sconfreq(f, 0);    /* Send initial Configure-Request */
			f->state = LS_REQSENT;
			break;
	}
}


/*
 * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
 */
static void
fsm_rconfnakrej(fsm* f, int code, int id, u_char* inp, int len)
{
	int (*proc)(fsm*, u_char*, int);
	int ret;

	FSMDEBUG(LOG_INFO, ("fsm_rconfnakrej(%s): Rcvd id %d state=%d (%s)\n",
	                    PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));

	if(id != f->reqid || f->seen_ack) {  /* Expected id? */
		return;        /* Nope, toss... */
	}

	proc = (code == CONFNAK) ? f->callbacks->nakci : f->callbacks->rejci;

	if(!proc || !((ret = proc(f, inp, len)))) {
		/* Nak/reject is bad - ignore it */
		FSMDEBUG(LOG_INFO, ("%s: received bad %s (length %d)\n",
		                    PROTO_NAME(f), (code == CONFNAK ? "Nak" : "reject"), len));
		return;
	}

	f->seen_ack = 1;

	switch(f->state) {
		case LS_CLOSED:
		case LS_STOPPED:
			fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
			break;

		case LS_REQSENT:
		case LS_ACKSENT:
			/* They didn't agree to what we wanted - try another request */
			UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */

			if(ret < 0) {
				f->state = LS_STOPPED;    /* kludge for stopping CCP */
			} else {
				fsm_sconfreq(f, 0);    /* Send Configure-Request */
			}

			break;

		case LS_ACKRCVD:
			/* Got a Nak/reject when we had already had an Ack?? oh well... */
			UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
			fsm_sconfreq(f, 0);
			f->state = LS_REQSENT;
			break;

		case LS_OPENED:

			/* Go down and restart negotiation */
			if(f->callbacks->down) {
				(*f->callbacks->down)(f);  /* Inform upper layers */
			}

			fsm_sconfreq(f, 0);    /* Send initial Configure-Request */
			f->state = LS_REQSENT;
			break;
	}
}


/*
 * fsm_rtermreq - Receive Terminate-Req.
 */
static void
fsm_rtermreq(fsm* f, int id, u_char* p, int len)
{
	LWIP_UNUSED_ARG(p);

	FSMDEBUG(LOG_INFO, ("fsm_rtermreq(%s): Rcvd id %d state=%d (%s)\n",
	                    PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));

	switch(f->state) {
		case LS_ACKRCVD:
		case LS_ACKSENT:
			f->state = LS_REQSENT;    /* Start over but keep trying */
			break;

		case LS_OPENED:
			if(len > 0) {
				FSMDEBUG(LOG_INFO, ("%s terminated by peer (%p)\n", PROTO_NAME(f), p));
			} else {
				FSMDEBUG(LOG_INFO, ("%s terminated by peer\n", PROTO_NAME(f)));
			}

			if(f->callbacks->down) {
				(*f->callbacks->down)(f);  /* Inform upper layers */
			}

			f->retransmits = 0;
			f->state = LS_STOPPING;
			TIMEOUT(fsm_timeout, f, f->timeouttime);
			break;
	}

	fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
}


/*
 * fsm_rtermack - Receive Terminate-Ack.
 */
static void
fsm_rtermack(fsm* f)
{
	FSMDEBUG(LOG_INFO, ("fsm_rtermack(%s): state=%d (%s)\n",
	                    PROTO_NAME(f), f->state, ppperr_strerr[f->state]));

	switch(f->state) {
		case LS_CLOSING:
			UNTIMEOUT(fsm_timeout, f);
			f->state = LS_CLOSED;

			if(f->callbacks->finished) {
				(*f->callbacks->finished)(f);
			}

			break;

		case LS_STOPPING:
			UNTIMEOUT(fsm_timeout, f);
			f->state = LS_STOPPED;

			if(f->callbacks->finished) {
				(*f->callbacks->finished)(f);
			}

			break;

		case LS_ACKRCVD:
			f->state = LS_REQSENT;
			break;

		case LS_OPENED:
			if(f->callbacks->down) {
				(*f->callbacks->down)(f);  /* Inform upper layers */
			}

			fsm_sconfreq(f, 0);
			break;

		default:
			FSMDEBUG(LOG_INFO, ("fsm_rtermack(%s): UNHANDLED state=%d (%s)!!!\n",
			                    PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}
}


/*
 * fsm_rcoderej - Receive an Code-Reject.
 */
static void
fsm_rcoderej(fsm* f, u_char* inp, int len)
{
	u_char code, id;

	FSMDEBUG(LOG_INFO, ("fsm_rcoderej(%s): state=%d (%s)\n",
	                    PROTO_NAME(f), f->state, ppperr_strerr[f->state]));

	if(len < HEADERLEN) {
		FSMDEBUG(LOG_INFO, ("fsm_rcoderej: Rcvd short Code-Reject packet!\n"));
		return;
	}

	GETCHAR(code, inp);
	GETCHAR(id, inp);
	FSMDEBUG(LOG_WARNING, ("%s: Rcvd Code-Reject for code %d, id %d\n",
	                       PROTO_NAME(f), code, id));

	if(f->state == LS_ACKRCVD) {
		f->state = LS_REQSENT;
	}
}


/*
 * fsm_protreject - Peer doesn't speak this protocol.
 *
 * Treat this as a catastrophic error (RXJ-).
 */
void
fsm_protreject(fsm* f)
{
	switch(f->state) {
		case LS_CLOSING:
			UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */

		/* fall through */
		case LS_CLOSED:
			f->state = LS_CLOSED;

			if(f->callbacks->finished) {
				(*f->callbacks->finished)(f);
			}

			break;

		case LS_STOPPING:
		case LS_REQSENT:
		case LS_ACKRCVD:
		case LS_ACKSENT:
			UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */

		/* fall through */
		case LS_STOPPED:
			f->state = LS_STOPPED;

			if(f->callbacks->finished) {
				(*f->callbacks->finished)(f);
			}

			break;

		case LS_OPENED:
			if(f->callbacks->down) {
				(*f->callbacks->down)(f);
			}

			/* Init restart counter, send Terminate-Request */
			f->retransmits = f->maxtermtransmits;
			fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
			          (u_char*) f->term_reason, f->term_reason_len);
			TIMEOUT(fsm_timeout, f, f->timeouttime);
			--f->retransmits;

			f->state = LS_STOPPING;
			break;

		default:
			FSMDEBUG(LOG_INFO, ("%s: Protocol-reject event in state %d (%s)!\n",
			                    PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
	}
}


/*
 * fsm_sconfreq - Send a Configure-Request.
 */
static void
fsm_sconfreq(fsm* f, int retransmit)
{
	u_char* outp;
	int cilen;

	if(f->state != LS_REQSENT && f->state != LS_ACKRCVD && f->state != LS_ACKSENT) {
		/* Not currently negotiating - reset options */
		if(f->callbacks->resetci) {
			(*f->callbacks->resetci)(f);
		}

		f->nakloops = 0;
	}

	if(!retransmit) {
		/* New request - reset retransmission counter, use new ID */
		f->retransmits = f->maxconfreqtransmits;
		f->reqid = ++f->id;
	}

	f->seen_ack = 0;

	/*
	 * Make up the request packet
	 */
	outp = outpacket_buf[f->unit] + PPP_HDRLEN + HEADERLEN;

	if(f->callbacks->cilen && f->callbacks->addci) {
		cilen = (*f->callbacks->cilen)(f);

		if(cilen > peer_mru[f->unit] - (int)HEADERLEN) {
			cilen = peer_mru[f->unit] - HEADERLEN;
		}

		if(f->callbacks->addci) {
			(*f->callbacks->addci)(f, outp, &cilen);
		}
	} else {
		cilen = 0;
	}

	/* send the request to our peer */
	fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);

	/* start the retransmit timer */
	--f->retransmits;
	TIMEOUT(fsm_timeout, f, f->timeouttime);

	FSMDEBUG(LOG_INFO, ("%s: sending Configure-Request, id %d\n",
	                    PROTO_NAME(f), f->reqid));
}


/*
 * fsm_sdata - Send some data.
 *
 * Used for all packets sent to our peer by this module.
 */
void
fsm_sdata(fsm* f, u_char code, u_char id, u_char* data, int datalen)
{
	u_char* outp;
	int outlen;

	/* Adjust length to be smaller than MTU */
	outp = outpacket_buf[f->unit];

	if(datalen > peer_mru[f->unit] - (int)HEADERLEN) {
		datalen = peer_mru[f->unit] - HEADERLEN;
	}

	if(datalen && data != outp + PPP_HDRLEN + HEADERLEN) {
		BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
	}

	outlen = datalen + HEADERLEN;
	MAKEHEADER(outp, f->protocol);
	PUTCHAR(code, outp);
	PUTCHAR(id, outp);
	PUTSHORT(outlen, outp);
	pppWrite(f->unit, outpacket_buf[f->unit], outlen + PPP_HDRLEN);
	FSMDEBUG(LOG_INFO, ("fsm_sdata(%s): Sent code %d,%d,%d.\n",
	                    PROTO_NAME(f), code, id, outlen));
}

#endif /* PPP_SUPPORT */
